From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AE47EC6FA99 for ; Fri, 10 Mar 2023 15:36:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234354AbjCJPg4 (ORCPT ); Fri, 10 Mar 2023 10:36:56 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53766 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234365AbjCJPge (ORCPT ); Fri, 10 Mar 2023 10:36:34 -0500 Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DC48010E252 for ; Fri, 10 Mar 2023 07:23:53 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id C539CCE2944 for ; Fri, 10 Mar 2023 15:12:39 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A66BAC433EF; Fri, 10 Mar 2023 15:12:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678461158; bh=//pQzCxhE4KZJii3zPgvNLZUMp7EQxAa0kZfU6dnOAo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tPhK1fv7sy6ipa4XSYjgdFLiWFA7XJtlodJonuFDCx/j5/EBXC+R51gMCl+VmpW3Z rj6ySlBjOcDp9oLHiOec0X+AmWaxg3z+W/b4gs/P/B86xvOPpZG7IDvQL66OiTUwHw 2JnakwdbvvyzZj956CY3jEnWTvgRck7KDwI+V5TY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Lu Wei , David Ahern , Paolo Abeni , Sasha Levin Subject: [PATCH 5.15 044/136] ipv6: Add lwtunnel encap size of all siblings in nexthop calculation Date: Fri, 10 Mar 2023 14:42:46 +0100 Message-Id: <20230310133708.407297294@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230310133706.811226272@linuxfoundation.org> References: <20230310133706.811226272@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Lu Wei [ Upstream commit 4cc59f386991ec9374cb4bc83dbe1c0b5a95033f ] In function rt6_nlmsg_size(), the length of nexthop is calculated by multipling the nexthop length of fib6_info and the number of siblings. However if the fib6_info has no lwtunnel but the siblings have lwtunnels, the nexthop length is less than it should be, and it will trigger a warning in inet6_rt_notify() as follows: WARNING: CPU: 0 PID: 6082 at net/ipv6/route.c:6180 inet6_rt_notify+0x120/0x130 ...... Call Trace: fib6_add_rt2node+0x685/0xa30 fib6_add+0x96/0x1b0 ip6_route_add+0x50/0xd0 inet6_rtm_newroute+0x97/0xa0 rtnetlink_rcv_msg+0x156/0x3d0 netlink_rcv_skb+0x5a/0x110 netlink_unicast+0x246/0x350 netlink_sendmsg+0x250/0x4c0 sock_sendmsg+0x66/0x70 ___sys_sendmsg+0x7c/0xd0 __sys_sendmsg+0x5d/0xb0 do_syscall_64+0x3f/0x90 entry_SYSCALL_64_after_hwframe+0x72/0xdc This bug can be reproduced by script: ip -6 addr add 2002::2/64 dev ens2 ip -6 route add 100::/64 via 2002::1 dev ens2 metric 100 for i in 10 20 30 40 50 60 70; do ip link add link ens2 name ipv_$i type ipvlan ip -6 addr add 2002::$i/64 dev ipv_$i ifconfig ipv_$i up done for i in 10 20 30 40 50 60; do ip -6 route append 100::/64 encap ip6 dst 2002::$i via 2002::1 dev ipv_$i metric 100 done ip -6 route append 100::/64 via 2002::1 dev ipv_70 metric 100 This patch fixes it by adding nexthop_len of every siblings using rt6_nh_nlmsg_size(). Fixes: beb1afac518d ("net: ipv6: Add support to dump multipath routes via RTA_MULTIPATH attribute") Signed-off-by: Lu Wei Reviewed-by: David Ahern Link: https://lore.kernel.org/r/20230222083629.335683-2-luwei32@huawei.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- net/ipv6/route.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 0655fd8c67e93..7b26882b9e70e 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -5555,16 +5555,17 @@ static size_t rt6_nlmsg_size(struct fib6_info *f6i) nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_nlmsg_size, &nexthop_len); } else { + struct fib6_info *sibling, *next_sibling; struct fib6_nh *nh = f6i->fib6_nh; nexthop_len = 0; if (f6i->fib6_nsiblings) { - nexthop_len = nla_total_size(0) /* RTA_MULTIPATH */ - + NLA_ALIGN(sizeof(struct rtnexthop)) - + nla_total_size(16) /* RTA_GATEWAY */ - + lwtunnel_get_encap_size(nh->fib_nh_lws); + rt6_nh_nlmsg_size(nh, &nexthop_len); - nexthop_len *= f6i->fib6_nsiblings; + list_for_each_entry_safe(sibling, next_sibling, + &f6i->fib6_siblings, fib6_siblings) { + rt6_nh_nlmsg_size(sibling->fib6_nh, &nexthop_len); + } } nexthop_len += lwtunnel_get_encap_size(nh->fib_nh_lws); } -- 2.39.2